Rename db_performance to migrations

Author: atodorov

README.rst

@@ -75,18 +75,21 @@ Features
 Additional plugins
 ------------------
 
-``pylint_django.checkers.db_performance`` looks for migrations which add new
-model fields and these fields have a default value. According to
-`Django docs <https://docs.djangoproject.com/en/2.0/topics/migrations/#postgresql>`__
-this may have performance penalties especially on large tables. The prefered way
-is to add a new DB column with ``null=True`` because it will be created instantly
-and then possibly populate the table with the desired default values.
+``pylint_django.checkers.migrations`` looks for migrations which:
+
+- add new model fields and these fields have a default value. According to
+  `Django docs <https://docs.djangoproject.com/en/2.0/topics/migrations/#postgresql>`_
+  this may have performance penalties especially on large tables. The prefered way
+  is to add a new DB column with ``null=True`` because it will be created instantly
+  and then possibly populate the table with the desired default values.
+  Only the last migration from a sub-directory will be examined;
+- are ``migrations.RunPython()`` without a reverse callable - these will result in
+  non reversible data migrations;
 
-Only the last migration from a sub-directory will be examined!
 
 This plugin is disabled by default! To enable it::
 
-    pylint --load-plugins pylint_django --load-plugins pylint_django.checkers.db_performance
+    pylint --load-plugins pylint_django --load-plugins pylint_django.checkers.migrations
 
 
 Known issues

pylint_django/checkers/db_performance.py renamed to pylint_django/checkers/migrations.py

@@ -1,10 +1,11 @@
-# Copyright (c) 2018 Alexander Todorov <atodorov@MrSenko.com>
+# Copyright (c) 2018, 2020 Alexander Todorov <atodorov@MrSenko.com>
+# Copyright (c) 2020 Bryan Mutai <mutaiwork@gmail.com>
 
 # Licensed under the GPL 2.0: https://www.gnu.org/licenses/old-licenses/gpl-2.0.html
 # For details: https://github.com/PyCQA/pylint-django/blob/master/LICENSE
 """
-Various DB performance suggestions. Disabled by default! Enable with
-pylint --load-plugins=pylint_django.checkers.db_performance
+Various suggestions around migrations. Disabled by default! Enable with
+pylint --load-plugins=pylint_django.checkers.migrations
 """
 
 import astroid

pylint_django/tests/test_func.py

@@ -51,14 +51,14 @@ def __init__(self, test_file):
         self._linter.load_plugin_configuration()
 
 
-class PylintDjangoDbPerformanceTest(PylintDjangoLintModuleTest):
+class PylintDjangoMigrationsTest(PylintDjangoLintModuleTest):
     """
         Only used so that we can load
-        pylint_django.checkers.db_performance into the linter!
+        pylint_django.checkers.migrations into the linter!
     """
     def __init__(self, test_file):
-        super(PylintDjangoDbPerformanceTest, self).__init__(test_file)
-        self._linter.load_plugin_modules(['pylint_django.checkers.db_performance'])
+        super().__init__(test_file)
+        self._linter.load_plugin_modules(['pylint_django.checkers.migrations'])
         self._linter.load_plugin_configuration()
 
 
@@ -74,7 +74,7 @@ def _file_name(test):
         if fname != '__init__.py' and fname.endswith('.py'):
             suite.append(FunctionalTestFile(input_dir, fname))
 
-    # when testing the db_performance plugin we need to sort by input file name
+    # when testing the migrations plugin we need to sort by input file name
     # because the plugin reports the errors in close() which appends them to the
     # report for the last file in the list
     if sort:
@@ -96,14 +96,14 @@ def test_everything(test_file):
     LintTest._runTest()
 
 
-# NOTE: define tests for the db_performance checker!
-DB_PERFORMANCE_TESTS = get_tests('input/migrations', True)
-DB_PERFORMANCE_TESTS_NAMES = [t.base for t in DB_PERFORMANCE_TESTS]
+# NOTE: define tests for the migrations checker!
+MIGRATIONS_TESTS = get_tests('input/migrations', True)
+MIGRATIONS_TESTS_NAMES = [t.base for t in MIGRATIONS_TESTS]
 
 
-@pytest.mark.parametrize("test_file", DB_PERFORMANCE_TESTS, ids=DB_PERFORMANCE_TESTS_NAMES)
-def test_db_performance_plugin(test_file):
-    LintTest = PylintDjangoDbPerformanceTest(test_file)
+@pytest.mark.parametrize("test_file", MIGRATIONS_TESTS, ids=MIGRATIONS_TESTS_NAMES)
+def test_migrations_plugin(test_file):
+    LintTest = PylintDjangoMigrationsTest(test_file)
     LintTest.setUp()
     LintTest._runTest()